CRS and rashes after 5F11-T. (A) A significantly lower proportion of patients experienced CRS after receiving 5F11-T than those in a prior trial of Hu19-CD828Z-Ts for patients with B-cell non-HL. (Fisher exact test, P = .043). (B) Patients receiving 5F11-T had lower rates of CRS, and CRS tended to start later, than in our prior experience with Hu19-CD828Z-Ts (log-rank test, P < .0001). (C) Of the patients receiving 5F11-T, a greater proportion of patients who had CRS also developed a rash than patients without CRS (Fisher exact test, P = .0075). (D) Patient 16 in cohort 1 developed a diffuse, grade 3 maculopapular rash starting on day +7 after 5F11-T infusion. The photo was taken on day +8. (E) Patient 16 in cohort 1 underwent a skin biopsy of the rash on day +7. Hematoxylin and eosin (H&E) staining at 20× original magnification reveals a spongiotic dermatitis with a lymphohistiocytic infiltrate and perivascular inflammation. (F) CD3 staining at 20× original magnification demonstrates superficial and deep perivascular T cells. (G) CD30 staining at 40× original magnification shows CD30-expressing lymphocytes in the dermis. No keratinocytes were found to be CD30⁺. (H) IHC staining for the CAR at 40× original magnification reveals scattered CAR⁺ cells in the dermis.